Point-to-multipoint microwave communication

ABSTRACT

A microwave communication system may include subscriber stations in communication with a base station. The stations may include time duplex circuitry normally found in wireless local area networks (WLANs). Signals normally routed through antennas associated with such circuitry instead are routed through circuitry to perform frequency conversion to and from microwave communications frequencies, for communications over microwave links between the subscriber stations and the base station. In some embodiments the wireless circuitry is configured for multiple input multiple output (MIMO) operation with one antenna port dedicated for transmission of data and one antenna port dedicated to reception of data.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/629,294, filed Sep. 27, 2012, which claims the benefit of U.S.Provisional Application No. 61/539,834, filed on Sep. 27, 2011, thedisclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates generally to microwave communication and,more particularly, to point-to-multipoint microwave communication.

Digital microwave radio may be used to provide communication betweenlocations. For example, mobile communication networks use microwavelinks to provide backhaul links from base stations. Digital microwaveradio systems have progressed in both capacity and cost. However, mostsystems are point-to-point, that is, they only provide communicationbetween two locations, or points, with each location having an antenna,a radio transceiver, and other associated electronics. A communicationnetwork made of point-to-point links is difficult to scale since addinga new location entails adding equipment both at the new location andanother location, such as a base station, with which the new locationwill communicate over a microwave link.

BRIEF SUMMARY OF THE INVENTION

Aspects of the invention relate to microwave communication systems. Inone aspect the invention provides a communication device for a microwavecommunication system, comprising: wireless communication circuitryincluding at least two antenna ports, with at least one of the twoantenna ports configured for transmission only and at least one other ofthe two antenna ports configured for reception only; at least onetransmit mixer coupled to the at least one antenna port configured fortransmission, to upconvert a signal from the at least one antenna portconfigured for transmission to provide a transmit signal at microwavecommunication frequencies; and at least one receive mixer coupled to theat least one other antenna port configured for reception, to downconverta received signal at microwave communication frequencies. In variousfurther aspects: the wireless communication circuitry is part of an802.11n device; the wireless communication circuitry is part of an802.11ac device; the wireless communication circuitry is configured totransmit and receive signals at frequencies in the 2.4 GHz band; thewireless communication circuitry is configured to transmit and receivesignals at frequencies in the 5 GHz band; the at least one transmitmixer is a direct conversion mixer; the at least one receive mixer is adirect conversion mixer; a transmit/receive switch is coupled to the atleast one transmit mixer and the at least one receive mixer; a firstlocal oscillator is coupled to the at least one transmit mixer, so as toprovide a first local oscillator signal to the at least one transmitmixer; a second local oscillator is coupled to the at least one receivemixer, so as to provide a second local oscillator signal to the at leastone receive mixer; a power amplifier is coupled to the at least onetransmit mixer and the diplexer; a low noise amplifier is coupled to theat least one receive mixer and the diplexer; and/or the at least onetransmit mixer and the at least one receive mixer are part of a radiofrequency front end (RFFE) unit.

In another aspect the invention provides a method useful in providingmicrowave communications, comprising: presenting a signal fortransmission on a first antenna port of a wireless communication devicehaving multiple input multiple output (MIMO) capability; upconvertingthe signal for transmission to a microwave communications frequency;downconverting a received signal from a microwave communicationsfrequency; and providing the downconverted signal to a second antennaport of the wireless access point device having MIMO capability. Invarious further aspects: the microwave communications frequency isbetween 6 GHz and 40 GHz; the signal for transmission is upconvertedfrom frequencies in the 2.4 GHz band; the signal for transmission isupconverted from frequencies in the 5 GHz band; the received signal isdownconverted to frequencies in the 2.4 GHz band; and/or the receivedsignal is downconverted to frequencies in the 5 GHz band.

In another aspect the invention provides a communications device for amicrowave communication system, comprising: wireless access pointcircuitry having multiple antenna ports, the circuitry configurable toplace a first antenna port of the multiple antenna ports in a transmitonly configuration and a second antenna port of the multiple antennaports in a receive only configuration; a microwave radio frequency frontend (RFFE) coupled to the first antenna port and the second antennaport, the microwave RFFE including circuitry to upconvert signals fromthe first antenna port to a microwave communications frequency andcircuitry to downconvert signals to the second antenna port from amicrowave communications frequency.

In another aspect the invention provides a point-to-multipoint microwavecommunication system, comprising: a microwave base station, comprising:a base station microwave antenna; wireless access point circuitryproviding for communication of data with spatial diversity betweentransmission of signals and reception of signals, the wireless accesspoint circuitry configured so as to transmit information from a firstantenna port and receive information from a second antenna port, thefirst antenna port and the second antenna port being different antennaports; and base station mixing circuitry for upconverting a signalreceived from the first antenna port from frequencies utilized intransmission of signals by the wireless access point to microwavecommunication frequencies and for downconverting a signal received fromthe base station microwave antenna from microwave communicationsfrequencies to frequencies utilized in reception of signals by thewireless access point; a plurality of microwave subscriber stations,each comprising: wireless subscriber unit circuitry coupled tocomponents of a subscriber station by way of a wired Ethernetconnection, the wireless subscriber unit circuitry providing forcommunication of data with spatial diversity between transmission ofsignals and reception of signals, the wireless subscriber unit circuitryconfigured so as to transmit information from a first antenna port andreceive information from a second antenna port, the first antenna portand the second antenna port being different antenna ports; a subscriberstation microwave antenna; and subscriber station mixing circuitryupconverting a signal received from the first antenna port fromfrequencies utilized in transmission of signals by the wirelesssubscriber unit to microwave communication frequencies and fordownconverting a signal received from the subscriber station microwaveantenna from microwave communications frequencies to frequenciesutilized in reception of signals by the wireless subscriber unit.

In another aspect the invention provides a communication device for amicrowave communication system, comprising: an 802.11n or an 802.11acdevice supporting at least a 2×2:1 MIMO configuration, the 2×2:1configuration including at least a first antenna port configured fortransmission only and at least a second antenna port configured forreception only; means for upconverting signals from the first antennaport to microwave communication frequencies; and means fordownconverting signals intended for the second port from microwavecommunication frequencies.

In another aspect the invention provides a communication device for amicrowave communication system, comprising: wireless communicationcircuitry including at least one antenna port, the wirelesscommunication circuitry providing for time duplexed communications; atransmit/receive switch coupled to the at least one antenna port by wayof a wired coupling; at least one transmit mixer coupled to thetransmit/receive switch to upconvert a signal from the transmit/receiveswitch to microwave communication frequencies; and at least one receivemixer coupled to the transmit/receive switch to downconvert a receivedsignal from microwave communication frequencies.

These and other aspects of the invention are more fully comprehendedupon review of this disclosure.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a diagram of a point-to-multipoint communication system inaccordance with aspects of the invention;

FIG. 2 is a simplified block diagram of a base station communicationdevice in accordance with aspects of the invention;

FIG. 3 is a simplified block diagram of subscriber communication devicein accordance with aspects of the invention;

FIG. 4 is a simplified block diagram of another base stationcommunication device in accordance with aspects of the invention;

FIG. 5 is a simplified block diagram of another subscriber communicationdevice in accordance with aspects of the invention.

FIG. 6 is a simplified block diagram of a further embodiment of a basestation communication device in accordance with aspects of theinvention;

FIG. 7 is a simplified block diagram of a further embodiment of asubscriber unit communication device in accordance with aspects of theinvention;

FIG. 8 is a simplified block diagram of a further embodiment of a basestation communication device in accordance with aspects of theinvention;

FIG. 9 is a simplified block diagram of a further embodiment of asubscriber unit communication device in accordance with aspects of theinvention;

FIG. 10 is a simplified block diagram of a further embodiment of asubscriber unit communication device in accordance with aspects of theinvention; and

FIG. 11 is a simplified block diagram of a further embodiment of asubscriber unit communication device in accordance with aspects of theinvention.

DETAILED DESCRIPTION

FIG. 1 is a diagram of a point-to-multipoint communication system inaccordance with aspects of the invention. The communication systemincludes a base station 101 that includes an antenna 103 fortransmitting and receiving radio signals. The antenna 103 of the basestation 101, in some embodiments, is a sector antenna and may have abeamwidth of, for example, 90 degrees. The base station 101 communicateswith a first subscriber station 111 via an antenna 113 approximate thefirst subscriber station. The base station also communicates with asecond subscriber station 121 via an antenna 123 approximate the secondsubscriber station and a third subscriber station 131 via an antenna 133approximate the third subscriber station. The antennas of the subscriberstations are, in some embodiments, dish antennas with narrow beamwidths.The subscriber stations may be located at various types of facilities.For example, as illustrated in FIG. 1, a subscriber station may be at aresidential building, an office building, or a tower of a mobilecommunication base station.

The base station and subscriber stations may communicate over links thatare frequency division duplex. That is, a station may transmit at onefrequency and receive at a different frequency. For example, the basestation may transmit at a band from 24.25 GHz to 24.45 GHz and receiveat a band from 25.05 GHz to 25.25 GHz, and these frequency bands may beconsidered to be about 25 GHz. In some embodiments, the base station andsubscriber stations may communicate over links that are time divisionduplex. That is, a station may transmit at certain times and receive atother times, in various embodiments at the same frequency. Additionally,the subscriber stations may transmit to the base station in a timedivision scheme so that each subscriber station transmits at a differenttime.

The antennas at each station are coupled to radio frequency front ends(RFFE), that are in turn coupled to devices operating in other, usuallylower frequencies which maybe termed baseband devices herein. Each RFFEgenerally includes a power amplifier for transmitting a microwave signaland a low noise amplifier for receiving a microwave signal. The RFFE mayalso include an upconverter and a downconverter to shift frequenciesbetween the microwave signals at the antenna and lower frequency signalsat the baseband device.

In some embodiments the baseband devices may be spatial division, timedivision devices, with for example spatial division features used,wholly or partially, to separate transmission channels and receptionchannels, and time division features used, wholly or partially, toseparate transmissions by different devices. In some embodiments thebaseband devices may be 802.11 devices, preferably 802.11n type devicesor 802.11ac devices. 802.11n and 802.11ac devices, which employmultiple-input multiple-output (MIMO) signaling, for example may beconsidered spatial-division, time-division duplex devices; however, thesystem adapts the spatial-division signals for use in microwave links,including frequency division microwave links.

FIG. 2 is a block diagram of a base station communication device inaccordance with aspects of the invention. The communication device maybe used, for example, at a base station in a point-to-multipointmicrowave communication system. The base station may provide a point ofpresence (POP) for telecommunication links, for example a fiber opticsystem linked to the Internet or a common carrier communication network,or provide a data communication pathway to a POP, with the base stationincluding circuitry to perform associated data processing or handling.The base station is in data communication with subscriber units by wayof the communication device.

The base station communication device effectively couples, from a datastandpoint, other components of the base station to subscriber units.The base station communication device receives and transmits digitalsignals from other components of the base station using wireless accesspoint circuitry 201. The digital signals may be transmitted and receivedfrom the other components of the base station by way of an Ethernetlink, for example. Additionally, the communication device may be poweredvia the Ethernet link, for example using Power over Ethernet (PoE)methods.

The wireless access point circuitry provides access point functions,including access point physical layer functions and Media Access Control(“MAC”) functions for the network formed by the base station and thesubscriber units. In the embodiment of FIG. 2, the wireless access pointcircuitry is a spatial division, time division device. Preferably thewireless access point circuitry 201 operates according to IEEE Std.802.11n or 802.11ac, and 802.11n chips, chipsets, and devices are widelyavailable, and in some embodiments, and as illustrated for conveniencein FIG. 2, the wireless access point circuitry may be provided in theform of an 802.11n or 802.11ac device.

An adapter 221 couples the wireless access point circuitry 201 to theRFFE 211. The wireless access point circuitry transmits and receivesradio frequency (RF) signals to and from the adapter, while the RFFEtransmits and receives intermediate frequency (IF) signals to and fromthe adapter. The adapter therefore upconverts and downconverts signalsas appropriate. The RFFE 211 is coupled to an antenna 213 fortransmission and reception of microwave signals, with the microwavesignal being transmitted to and received from for example subscriberunits. The RFFE 211, in some embodiments, is configured as an outdoorunit (ODU). In some embodiments, the adapter 221 is positioned remotelyfrom the RFFE 211, which for example may be positioned outdoors in thevicinity of the antenna, while the adapter is positioned approximateother base station components. The adapter 221 may be coupled to theRFFE 211 by a single coaxial cable.

The wireless access point circuitry includes at least two antenna ports,with two antenna ports as illustrated in FIG. 2. In most embodiments thewireless access point circuitry provides a MIMO capable device,supporting at least a 2×2:1 configuration, with one antenna portselected for transmission and one antenna port selected for reception,providing for spatial division of transmission and reception channels.In the event commercially available 802.11n or 802.11ac devices areutilized for the wireless access point circuitry, preferably suchdevices allow for explicit selection of antenna port usage, for exampleby way of register settings or otherwise.

The adapter 221 is coupled to a first antenna port of the wirelessaccess point circuitry 201 to receive a radio frequency signaltransmitted from the wireless access point circuitry 201. The adapter221 is also coupled to a second antenna port of the wireless accesspoint circuitry 201 to supply a radio frequency signal to the wirelessaccess point circuitry 201. In most embodiments the connections are byway of wired connections, as opposed to wireless connections. Thewireless access point circuitry 201 is configured to operate the firstantenna port as a transmit-only antenna and the second antenna port as areceive-only antenna. In various embodiments, the antenna ports of thewireless access point 201 operate at frequencies from 2.4 GHz to 2.5 GHzreferred to herein as a 2.4 GHz band or at frequencies from about 4.9GHz to about 6 GHz referred to herein as a 5 GHz band.

In the adapter, a transmit mixer 223 mixes the signal transmitted fromthe first antenna port of the wireless access point circuitry 201 with afirst local oscillator signal LO₁. The output of the transmit mixer 223is an intermediate frequency transmit signal that will be upconvertedfor microwave transmission by the RFFE 211. For example, the transmitsignal may be at 2.45 GHz and the first local oscillator signal may beat a frequency of 2.10 GHz to produce an intermediate frequency transmitsignal at 350 MHz. The frequency of the intermediate frequency transmitsignal may be tuned by adjusting the frequency of the first localoscillator signal and/or the frequency of the signal provided by thewireless access point circuitry through the first antenna port. Thetransmit mixer 223 preferably has low phase noise to avoid impairing thesignal transmitted from the communication device.

A diplexer 225 receives the intermediate frequency transmit signal andsupplies the signal to a combiner 229. The combiner 229 combines theintermediate frequency transmit signal with power and control signalsfrom a control block 228. The power signal is typically a DC signal andthe control signals are low frequency, relative to the intermediatefrequency, and control operation of the RFFE 211, such as transmit powerlevels and microwave frequencies. The combined signals from the combiner229 are supplied to the RFFE 211, which upconverts the intermediatefrequency transmit signal to a microwave signal for transmission via theantenna 213.

The diplexer 225 also receives, via the combiner 229, an intermediatefrequency receive signal from the RFFE 211. The intermediate frequencyreceive signal is a downconverted version of the microwave signalreceived by the antenna 213. The diplexer 225 separates the intermediatefrequency receive signal and supplies it to a receive mixer 227 thatmixes the intermediate frequency receive signal with second localoscillator signal LO₂. The output of the receive mixer 227 is suppliedto the second antenna port of the wireless access point 201. The receivemixer 227 upconverts the intermediate frequency receive signal to thefrequency of the wireless access point circuitry 201. For example, theintermediate frequency receive signal may be at 140 MHz and the secondlocal oscillator signal may be at a frequency of 2.31 GHz to supply asignal to the wireless access point 201 at 2.45 GHz. The frequency ofthe intermediate frequency receive signal may be tuned by adjusting thefrequency of the second local oscillator signal and/or adjusting thefrequency of the signal expected to be received by the wireless accesspoint 201 on the second antenna port. The receive mixer 227 preferablehas low phase noise to avoid impairing the signal supplied to thewireless access point 201.

In various embodiments the local oscillator signals LO₁ and LO₂ may befrequency locked to corresponding signals of a subscriber stationcommunication device in communication with the base station. In variousembodiments the frequency locking may be accomplished by using a GPSreference signal at both stations, a pilot tone communicated between thetwo stations, use of very stable oscillators at both stations, or othermethods.

FIG. 3 is a block diagram of a subscriber unit communication device inaccordance with aspects of the invention. The communication device maybe used, for example, at a subscriber station in a point-to-multipointmicrowave communication system. The subscriber unit communication deviceof FIG. 3 is configured to receive a microwave signal transmitted fromthe base station communication device of FIG. 2 and vice versa. Thecommunication device of FIG. 3 is similar to the communication device ofFIG. 2, with the wireless access point circuitry being replaced bywireless subscriber unit circuitry. In various embodiments, however, thecircuitry to provide the wireless access point functions may be the sameas the circuitry to provide the wireless subscriber unit functions, orpartially or completely separate circuitry to provide both functions maybe provided together in a single device.

In somewhat more detail, similar to the base station communicationdevice, the subscriber unit communication device has wireless subscriberunit circuitry 301 for interfacing with subscriber system components,such as a subscriber system local area network. Radio frequency data toand from the wireless subscriber unit circuitry is upconverted ordownconverted to IF by an adapter 321, which is coupled to an RFFE 311,which communicates using microwave signals with a base station.

The wireless subscriber unit circuitry 301 sends and receives data tosubscriber system components, for example in the form of a local areanetwork at a subscriber's premises. The data between the wirelesssubscriber unit circuitry and the local area network may becommunicated, for example, using Ethernet protocols. The wirelesssubscriber unit circuitry performs wireless network subscriber unitfunctions, for example physical layer functions and MAC functions.Preferably the functions are performed in accordance with 802.11n or802.11ac, with the wireless subscriber unit having at least two antennaports and being a MIMO capable device, supporting at least a 2×2:1configuration. As with the wireless access point circuitry, the wirelesssubscriber unit circuitry includes a first antenna port and a secondantenna port, with one of the ports, for example the first antenna port,configured to provide radio frequency transmit data and the other port,for example the second antenna port, configured to receive radiofrequency receive data. As with the communication device of FIG. 2, inmost embodiments the couplings or connections between the antenna portsand the adapter are wired couplings or connections, as opposed towireless couplings or connections. Also as with the wireless accesspoint circuitry, preferably the wireless subscriber unit circuitry canbe configured to have one antenna port configured for transmit data andone antenna port configured for receive data, for example through theuse of register settings.

As with the base station adapter, using a mixer 327, the subscriber unitadapter 321 downconverts radio frequency transmit data to anintermediate frequency expected to be received by an RFFE 311, and usinga mixer 323 upconverts an intermediate frequency signal provided by theRFFE to a radio frequency signal expected to be received by the wirelesssubscriber unit circuitry. A diplexer 325 is in the signal path betweenthe RFFE and the mixers, with the diplexer splitting the signals to andfrom the mixers. As illustrated in the embodiment of FIG. 3, a combiner329 is in a signal path between the diplexer and the RFFE. The combinerallows for insertion and removal of control signals from theintermediate frequency signals.

The RFFE receives or transmits the intermediate frequency signals fromor to the adapter, and upconverts or downconverts the respectiveintermediate frequency signals to or from microwave signals, which aretransmitted or received by an antenna 313. The microwave signals aregenerally communicated to or from a base station. In various embodimentsthe local oscillator signals may be frequency locked to correspondinglocal oscillator signals in the base station, for example as discussedwith respect to FIG. 2.

FIG. 4 is a block diagram of another base station communication devicein accordance with aspects of the invention. The communication devicemay be used, for example, at a base station in a point-to-multipointmicrowave communication system. The communication device of FIG. 4 issimilar to the communication device of FIG. 2. The communication deviceof FIG. 4 receives and transmits digital signals from and to othercomponents of the base station using wireless access point circuitry 401and transmits and receives microwave signals to and from subscriberstations, a plurality of subscriber stations in most embodiments, via anantenna 413. The microwave signals, which may be termed microwavecommunication signals herein, may be in any band of microwavefrequencies, in some embodiments between 6 GHz and 40 GHz forpoint-to-multipoint microwave communication. As an example microwavecommunication signals may be at about 25 GHz, and particularly in theband of frequencies from about 24.25 GHz to about 24.45 GHz and fromabout 25.05 GHz to about 25.25 GHz in some embodiments. In variousembodiments the microwave signals may be in any band of microwavefrequencies between 6 GHz and 40 GHz. In some embodiments microwavesignals are in a block of frequencies about one or all of 28 GHz, 31GHz, and/or 39 GHz.

The wireless access point circuitry 401 may be similar to or the same asthe wireless access point circuitry of the embodiment of FIG. 2. Thewireless access point circuitry performs wireless access pointfunctions, including physical layer functions and MAC functions, and forexample including access point communication medium contention relatedprocessing, preferably in accordance with 802.11n or 802.11ac. Thewireless access point circuitry is configured to operate a first antennaport as a transmit-only antenna and a second antenna port as areceive-only antenna, providing for spatial multiplexing of transmit andreceive channels. In various embodiments, the antenna ports of thewireless access point 401 operate at frequencies about 2.4 or 5 GHz. Asignal transmitted from the first antenna port is supplied to a transmitmixer 423, in most embodiments by way of wired, as opposed to wireless,couplings or connections. The transmit mixer 423 mixes the transmitsignal from the wireless access point 401 with a first local oscillatorsignal LO₁ to upconvert the transmit signal from the wireless accesspoint 401 to a microwave transmit signal. For example, the transmitsignal from the wireless access point 401 may be at 5.8 GHz and thefirst local oscillator signal may be at a frequency of 18.45 GHz toproduce the microwave transmit signal at 24.25 GHz. The frequency of themicrowave transmit signal may be tuned by adjusting the frequency of thefirst local oscillator signal and/or the frequency of the transmitsignal from the wireless access point 401. The microwave transmit signalis amplified by power amplifier 425 and coupled to the antenna 413 by adiplexer 427.

The diplexer 427 also supplies a microwave signal received by theantenna to a low noise amplifier 431. The low noise amplifier 431supplies an amplified version of the microwave receive signal to areceive mixer 433 that mixes the microwave receive signal with secondlocal oscillator signal LO₂. The output of the receive mixer 433 issupplied to the second antenna port of the wireless access point 401, inmost embodiments by way of a wired, as opposed to wireless, couplings orconnections. The receive mixer 433 downconverts from the microwavesignal frequency to the frequency of the wireless access point 401. Forexample, the microwave receive signal may be at 25.05 GHz and the secondlocal oscillator signal may be at a frequency of 19.25 GHz to supply thesignal to the wireless access point 401 at 5.8 GHz. Frequency tuning ofthe microwave receive signal may be effected by adjusting the frequencyof the second local oscillator signal and/or tuning of the signalreceived by the wireless access point 401. In contrast to thecommunication device of FIG. 2, the communication device of FIG. 4converts between the frequencies of the wireless access point and themicrowave frequencies directly without producing intermediate frequencysignals.

In some embodiments the local oscillators, power amplifiers, low noiseamplifier, and diplexer may be part of a microwave RFFE 421. In variousembodiments the local oscillators may be frequency locked withcorresponding local oscillator signals of subscriber stations, forexample as discussed with respect to FIG. 2.

FIG. 5 is a block diagram of another subscriber unit communicationdevice in accordance with aspects of the invention. The communicationdevice may be used, for example, at a subscriber station in apoint-to-multipoint microwave communication system. The communicationdevice of FIG. 5 is configured, in a communications network, to receivea microwave signal transmitted from the communication device of FIG. 4and vice versa. The communication device of FIG. 5 may also be used withthe communication device of FIG. 2, and the communication device of FIG.4 may also be used with the communication device of FIG. 3. Thecommunication device of FIG. 5 is similar to the communication device ofFIG. 4. However, wireless subscriber unit circuitry is utilized in placeof wireless access point circuitry, although in some embodiments commoncircuitry may provide both wireless access point functions and wirelesssubscriber unit functions. The wireless subscriber unit provides forspatial multiplexing of transmit and receive channels, for examplethrough the use of different wireless subscriber unit circuitry antennaports for transmission and receive channels. The wireless subscriberunit circuitry also provides, in many embodiments, contention avoidancefunctions in multi-subscriber unit environments, for example through theuse of time division communication schemes.

In the communication device of FIG. 5, the wireless subscriber unitcircuitry is in data communication with other components of a subscriberstation, for example by way of a wired connection utilizing Ethernetcommunication protocols. The wireless subscriber unit circuitry providessubscriber unit functions, including physical layer functions and MACfunctions, preferably in accordance with 802.11n or 802.11ac. A firstantenna port of the wireless subscriber unit circuitry is configured fortransmit-only operation, with the first antenna port coupled to atransmit mixer 523. The transmit mixer upconverts a signal from thefirst antenna port to a microwave transmit signal, which is amplified bya power amplifier 525 and sent to an antenna 513 by way of a diplexer527. As with the device of FIG. 4, in most embodiments the coupling orconnection between the first antenna port and the mixer is a wired, asopposed to wireless, coupling or connection.

The diplexer also supplies a microwave signal received by the antenna toa low noise amplifier 531. The amplified received microwave signal isdownconverted by a receive mixer 533, with the downconverted signalhaving a frequency about a frequency expected to be received by thewireless subscriber unit circuitry. The downconverted signal is providedto a second antenna port of the wireless subscriber unit circuitry, withthe second antenna port configured for receive-only operation. As withthe device of FIG. 4, in most embodiments the coupling or connectionbetween the second antenna port and the mixer is a wired, as opposed towireless, coupling or connection.

In some embodiments the local oscillators, power amplifiers, low noiseamplifier, and diplexer may be part of a microwave RFFE 521. In variousembodiments the local oscillators may be frequency locked withcorresponding local oscillator signals of a base station, for example asdiscussed with respect to FIG. 2.

FIG. 6 is a block diagram of a further embodiment of a base stationcommunication device in accordance with aspects of the invention. Theembodiment of FIG. 6 is similar to the embodiment of FIG. 2, withwireless access point circuitry 601 in data communication with otherportions of a base station, by way of for example an Ethernetconnection. The wireless access point circuitry is also in datacommunication with subscriber units by way of a transmit/receive switch604, an adapter 621, an RFFE 611, and a microwave antenna 613. In theembodiment of FIG. 6, however, the transmit/receive switch 604, notpresent in the embodiment of FIG. 2, provides for separation of transmitand receive communication channels, with the wireless access pointcircuitry 601 providing time division access point functions in, forexample, a multi-subscriber unit environment. As the transmit/receiveswitch provides for separation of transmit and receive channels, thewireless access point circuitry need not provide MIMO functions, and thewireless access point circuitry may provide, as illustrated in FIG. 6, asingle antenna port, connected or coupled in most embodiments to thetransmit receive switch by wired, as opposed to wireless, connections orcouplings. In various embodiments the wireless access point circuitryoperates in conformance with 802.11a, 802.11b, or 802.11g, and may becomprised of an 802.11a, 802.11b, or 802.11g chip, chipset, or device.Also, in various embodiments frequency of operation of local oscillatorsused for upconverting and downconverting signals in the transmit andreceive channels may be different than those of the embodiment of FIG.2, to account for differing frequencies that may be transmitted orexpected to be received by the wireless access point circuitry. Invarious embodiments the local oscillators may be frequency locked withcorresponding local oscillator signals of subscriber stations, forexample as discussed with respect to FIG. 2.

FIG. 7 is a block diagram of a further embodiment of a subscriber unitcommunication device in accordance with aspects of the invention. Theembodiment of FIG. 7 is similar to the embodiment of FIG. 3, withwireless subscriber circuitry 701 in data communication with otherportions of a subscriber unit, by way of for example an Ethernetconnection, and a base station by way of a transmit/receive switch 704,an adapter 721, an RFFE 711, and a microwave antenna 713. In theembodiment of FIG. 7, however, the transmit/receive switch 704, notpresent in the embodiment of FIG. 3, provides for separation of transmitand receive communication channels, with the wireless subscriber unitcircuitry 701 providing time division subscriber unit functions in, forexample, a multi-subscriber unit environment. As the transmit/receiveswitch provides for separation of transmit and receive channels, thewireless subscriber unit circuitry need not provide MIMO functions, andthe wireless subscriber unit circuitry may provide, as illustrated inFIG. 6, a single antenna port. In most embodiments the antenna port isconnected or coupled to the transmit/receive switch by wired connectionsor couplings. In various embodiments the wireless subscriber unitcircuitry operates in conformance with 802.11a, 802.11b, or 802.11g, andmay be comprised of an 802.11a, 802.11b, or 802.11g chip, chipset, ordevice. Also, in various embodiments frequency of operation of localoscillators used for upconverting and downconverting signals in thetransmit and receive channels may be different than those of theembodiment of FIG. 3, to account for differing frequencies that may betransmitted or expected to be received by the wireless access pointcircuitry. In various embodiments the local oscillators may be frequencylocked with corresponding local oscillator signals of a base station,for example as discussed with respect to FIG. 2.

FIG. 8 is a block diagram of a further embodiment of a base stationcommunication device in accordance with aspects of the invention. Theembodiment of FIG. 8 is similar to the embodiment of FIG. 4, withwireless access point circuitry 801 in data communication with otherportions of a base station, by way of for example an Ethernetconnection, and, by way of an RFFE 821 including a transmit/receiveswitch 804, a microwave antenna 813 for communicating with subscriberunits. In the embodiment of FIG. 8, however, the transmit/receive switch804 provides for separation of transmit and receive communicationchannels, with the wireless access point circuitry 801 providing timedivision access point functions in, for example, a multi-subscriber unitenvironment. As the transmit/receive switch provides for separation oftransmit and receive channels, the wireless access point circuitry neednot provide MIMO functions, and the wireless access point circuitry mayprovide, as illustrated in FIG. 8, a single antenna port. In mostembodiments the antenna port is connected or coupled to thetransmit/receive switch by way of wired, as opposed to wireless,connection or coupling. In various embodiments the wireless access pointcircuitry operates in conformance with 802.11a, 802.11b, or 802.11g, andmay be comprised of an 802.11a, 802.11b, or 802.11g chip, chipset, ordevice. Also, in various embodiments frequency of operation of localoscillators used for upconverting and downconverting signals in thetransmit and receive channels may be different than those of theembodiment of FIG. 4, to account for differing frequencies that may betransmitted or expected to be received by the wireless access pointcircuitry. In various embodiments the local oscillators may be frequencylocked with corresponding local oscillator signals of subscriberstations, for example as discussed with respect to FIG. 2.

FIG. 9 is a block diagram of a further embodiment of a subscriber unitcommunication device in accordance with aspects of the invention. Theembodiment of FIG. 9 is similar to the embodiment of FIG. 5, withwireless subscriber circuitry 901 in data communication with otherportions of a subscriber unit, by way of for example an Ethernetconnection, and, by way of an RFFE 921 including a transmit/receiveswitch 904, a microwave antenna 913 for communicating with a basestation. In the embodiment of FIG. 7, however, the transmit/receiveswitch 904 provides for separation of transmit and receive communicationchannels, with the wireless subscriber unit circuitry 901 providing timedivision subscriber unit functions in, for example, a multi-subscriberunit environment. As the transmit/receive switch provides for separationof transmit and receive channels, the wireless subscriber unit circuitryneed not provide MIMO functions, and the wireless subscriber unitcircuitry may provide, as illustrated in FIG. 9, a single antenna port.In most embodiments the antenna port is connected or coupled to thetransmit/receive switch by way of wired, as opposed to wireless,connections or couplings. In various embodiments the wireless subscriberunit circuitry operates in conformance with 802.11a, 802.11b, or802.11g, and may be comprised of an 802.11a, 802.11b, or 802.11g chip,chipset, or device. Also, in various embodiments frequency of operationof local oscillators used for upconverting and downconverting signals inthe transmit and receive channels may be different than those of theembodiment of FIG. 5, to account for differing frequencies that may betransmitted or expected to be received by the wireless access pointcircuitry. In various embodiments the local oscillators may be frequencylocked with corresponding local oscillator signals of a base station,for example as discussed with respect to FIG. 2.

FIG. 10 is a block diagram of a base station in accordance with aspectsof the invention. The base station of FIG. 10 is similar to the basestation of FIG. 4, and except as discussed below the discussion relatingto the base station of FIG. 4 applies to the base station of FIG. 10.

For the base station of FIG. 10, microwave signals are transmitted fromand received by a base station antenna 1021. In the system of FIG. 10,the transmitted and received microwave signals are both at the samefrequency, with the microwave communications being time duplexed insteadof being frequency duplexed, as for example in implementations of thebase station of FIG. 4. Accordingly, in the base station of FIG. 10, atransmit path from a transmit antenna port of wireless access pointcircuitry 1011 includes a transmit/receive switch 1019, in addition to afrequency converter 1013 and a power amplifier 1017. The receive path toa receive antenna port of the wireless access point circuitry similarlyincludes the transmit/receive switch, in addition to a low noiseamplifier 1025 and a frequency converter 1015. As transmitted andreceived signals are nominally at the same frequency, a common localoscillator signal may be used in various embodiments for both frequencyconverters.

The transmit/receive switch and the power amplifier also receive anon/off trigger signal from the wireless access point circuitry. Thetrigger signal places the transmit/receive switch in either transmitmode or receive mode. The trigger signal also enables and disables thepower amplifier, enabling the power amplifier so as to allowtransmission of data, and disabling the power amplifier when the systemis not transmitting data so as to not overwhelm received signals.

FIG. 11 is a block diagram of a subscriber station in accordance withaspects of the invention. Similar to the discussion with respect to thecorresponding base station of FIG. 10, the subscriber station of FIG. 11is similar to the subscriber station of FIG. 5.

For the subscriber station of FIG. 11, microwave signals are transmittedfrom and received by a subscriber station antenna 1121. In the system ofFIG. 11, the transmitted and received microwave signals are both at thesame frequency, with the microwave communications being time duplexedinstead of being frequency duplexed, as for example in implementationsof the base station of FIG. 5. Accordingly, in the subscriber station ofFIG. 11, a transmit path from a transmit antenna port of wirelesssubscriber unit circuitry 1111 includes a transmit/receive switch 1119,in addition to a frequency converter 1113 and a power amplifier 1117.The receive path to a receive antenna port of the wireless subscriberunit circuitry similarly includes the transmit/receive switch, inaddition to a low noise amplifier 1125 and a frequency converter 1115.As transmitted and received signals are nominally at the same frequency,a common local oscillator signal may be used in various embodiments forboth frequency converters.

The transmit/receive switch and the power amplifier also receive anon/off trigger signal from the wireless subscriber unit circuitry. Thetrigger signal places the transmit/receive switch in either transmitmode or receive mode. The trigger signal also enables and disables thepower amplifier, enabling the power amplifier so as to allowtransmission of data, and disabling the power amplifier when the systemis not transmitting data so as to not overwhelm received signals.

Although the invention has been described with respect to variousembodiments, it should be recognize that the invention comprises thenovel and non-obvious claims supported by this disclosure, along withtheir insubstantial variations.

What is claimed is:
 1. A method useful in providing microwavecommunications, comprising: presenting a signal for transmission on afirst antenna port of a wireless communication device having multipleinput multiple output (MIMO) capability; upconverting the signal fortransmission to a microwave communications frequency; downconverting areceived signal from a microwave communications frequency; and providingthe downconverted signal to a second antenna port of the wirelesscommunication device having MIMO capability; wherein the wirelesscommunication device is an 802.11n or 802.11ac device which is coupledto components of a subscriber station by way of a wired Ethernetconnection.
 2. The method of claim 1, wherein the first antenna port isconfigured to transmit signals only and the second antenna port isconfigured to receive signals only.
 3. The method of claim 2, whereinthe first antenna port and the second antenna port provide spatialseparation of transmit and receive channels.
 4. The method of claim 1further comprising performing physical layer and media access controlfunctions.
 5. The method of claim 1, wherein the microwavecommunications frequency is a frequency between 6 GHz and 40 GHz.
 6. Acommunication device for a microwave communication system, comprising:wireless communications circuitry having multiple antenna ports, thecircuitry configured to place a first antenna port of the multipleantenna ports in a transmit only configuration and a second antenna portof the multiple antenna ports in a receive only configuration, and toupconvert signals from baseband to wireless communications frequenciesand present the upconverted signals on the first antenna port, and todownconvert signals on the second antenna port from wirelesscommunications frequencies to baseband; a microwave radio frequencyfront end (RFFE) coupled to the first antenna port and the secondantenna port, the microwave RFFE including circuitry to upconvertsignals from the first antenna port from the wireless communicationsfrequencies to a microwave communications frequency and circuitry todownconvert signals to the second antenna port from a microwavecommunications frequency to the wireless communications frequencies;wherein the wireless communications circuitry comprises wirelesssubscriber station circuitry.
 7. The device of claim 6 furthercomprising an adapter, the adapter including at least one transmit mixerand at least one receive mixer, the at least one transmit mixer coupledto the first antenna port and the at least one receive mixer coupled tothe second antenna port.
 8. The device of claim 7, wherein the adapterfurther comprising a diplexer coupled to the at least one transmit mixerand the at least one receive mixer.
 9. The device of claim 8, whereinthe diplexer is, further coupled to a microwave antenna port, with thediplexer couplings arranged such that a signal received at the microwaveantenna port through a microwave antenna coupled to the microwaveantenna port is provided to the at least one receive mixer, and a signalreceived at the diplexer from the at least one transmit mixer isprovided to the microwave antenna port.
 10. The device of claim 7,wherein the first antenna port and the second antenna port are wiredlycoupled to the adapter.
 11. The device of claim 6 further comprising: afirst local oscillator coupled to at least one transmit mixer so as toprovide a first local oscillator signal to the at least one transmitmixer; a second local oscillator coupled to at least one receive mixerso as to provide a second local oscillator signal to the at least onereceive mixer; a power amplifier coupled to the at least one transmitmixer; a low noise amplifier coupled to the at least one receive mixer;and a diplexer coupled to the power amplifier, the low noise amplifierand a microwave antenna port, with the diplexer couplings arranged suchthat a signal received at the microwave antenna port through a microwaveantenna coupled to the microwave antenna port is provided to the atleast one receive mixer by way of the low noise amplifier and a signalreceived at the diplexer from the at least one transmit mixer by way ofthe power amplifier is provided to the microwave antenna port.
 12. Thedevice of claim 11, wherein the at least one transmit mixer, the atleast one receive mixer, the first local oscillator, the second localoscillator, the power amplifier, the low noise amplifier, and thediplexer are part of the RFFE.